Reporter incompetence alert: there is no such thing as “ commercial airspace”.
I have operated out of Chicago’s Midway, and once departure sent me off on a heading and altitude that took me right into one of the arrival gates (a fix in the sky) for ORD. Happily I saw the oncoming conga line of heavy iron in plenty of time to divert, but I was not happy with what could have happened.
Upon further research, it turns out that it is very difficult to find the current arrival routing that is used based on local ATC custom. These are not published in places that pilots can get their hands on reliably. Sure there are terminal and sectional charts, SID, STAR, etc. But other routings? Maybe things have changed.
For example, when the wind is out of the west and STL is using 30L & 30R, where is the arrival gate in far western Illinois? I know where it is by experience, but I have yet to find it on a published (official) map.